Investigation of neutralization mechanism of incinerated ash landfill layer by highly dissolved solution of carbon dioxide

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K12227
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: Meisei University
• Principal Investigator: Miyawaki Kentaro 明星大学, 理工学部, 教授 (00289521)
• Co-Investigator(Kenkyū-buntansha): 遠藤 和人 国立研究開発法人国立環境研究所, 福島支部, 室長 (10353533)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 焼却灰中和 / ウルトラファインバブル / 浸出水pH

Outline of Final Research Achievements

Assuming a final waste landfill with high leachate pH, this study investigated the gradual neutralization of an incinerator ash layer by injecting a high CO2 dissolved solution into the incinerator ash layer. A solution of about 1400 mg-CO2/L was generated, and it was confirmed that a certain level of CO2 supply was possible by passing the solution through a glass bead simulated landfill layer. The solution was also passed through the incinerator ash layer, and it was confirmed that the pH of the simulated leachate decreased. The formation of calcium carbonate was estimated from SEM-EDX measurements of the incinerated ash particle surfaces after the experiment.

Free Research Field

廃棄物工学

Academic Significance and Societal Importance of the Research Achievements

学術的な意義としては、CO2は水への溶存性が高い気体であり、CO2を溶存させたウルトラファインバブル（UFB）の計測事例はほとんど存在しなかった。本研究でUFB計数を実施したところ、今回の実験条件では存在量は少ないことが明らかとなった。社会的意義としては、二酸化炭素高溶存溶液を用いることで焼却灰層の穏やかな中和を進め、安定的に浸出水pHを低下させることが可能なことを明らかにした。